//解决ie9不兼容的Object.assign问题 
if (typeof Object.assign != 'function') {
	Object.assign = function(target) {
		'use strict';
		if (target == null) {
			throw new TypeError('Cannot convert undefined or null to object');
		}

		target = Object(target);
		for (var index = 1; index < arguments.length; index++) {
			var source = arguments[index];
			if (source != null) {
				for (var key in source) {
					if (Object.prototype.hasOwnProperty.call(source, key)) {
						target[key] = source[key];
					}
				}
			}
		}
		return target;
	};
}